diff --git a/src/base/abci/abc.c b/src/base/abci/abc.c
index b9535f423..36c8f698b 100644
--- a/src/base/abci/abc.c
+++ b/src/base/abci/abc.c
@@ -19700,7 +19700,7 @@ int Abc_CommandIf( Abc_Frame_t * pAbc, int argc, char ** argv )
             globalUtilOptind++;
             if ( strlen(pPars->pLutStruct) != 2 && strlen(pPars->pLutStruct) != 3 )
             {
-                Abc_Print( -1, "Command line switch \"-J\" should be followed by a 2- or 3-char string (e.g. \"66\" or \"666\").\n" );
+                Abc_Print( -1, "Command line switch \"-J\" should be followed by a 2-char string (e.g. \"44\" or \"66\" \").\n" );
                 goto usage;
             }
             break;
@@ -19883,7 +19883,7 @@ int Abc_CommandIf( Abc_Frame_t * pAbc, int argc, char ** argv )
         }
         if ( pPars->fEnableStructN )
         {
-            pPars->pFuncCell = pPars->fDelayOptLut ? NULL : If_CutPerformCheck66;
+            pPars->pFuncCell = pPars->fDelayOptLut ? NULL : If_CutPerformCheckXX;
         }
         else
         {
diff --git a/src/map/if/acd/ac_wrapper.cpp b/src/map/if/acd/ac_wrapper.cpp
index 6ee265318..7914bbd42 100644
--- a/src/map/if/acd/ac_wrapper.cpp
+++ b/src/map/if/acd/ac_wrapper.cpp
@@ -19,7 +19,7 @@
 #include "ac_wrapper.h"
 #include "ac_decomposition.hpp"
 #include "acd66.hpp"
-#include "acd666.hpp"
+#include "acdXX.hpp"
 
 ABC_NAMESPACE_IMPL_START
 
@@ -113,61 +113,49 @@ int acd_decompose( word * pTruth, unsigned nVars, int lutSize, unsigned *pdelay,
   }
 }
 
-int acd66_evaluate( word * pTruth, unsigned nVars, int compute_decomposition )
+inline int acd66_decompose( word * pTruth, unsigned nVars, unsigned char *decomposition )
 {
   using namespace acd;
-
   acd66_impl acd( nVars, true, false );
 
   if ( acd.run( pTruth ) == 0 )
     return 0;
-  
-  if ( !compute_decomposition )
+  if ( decomposition == NULL )
     return 1;
-
   int val = acd.compute_decomposition();
   if ( val != 0 )
   {
     return 0;
   }
+  acd.get_decomposition( decomposition );
 
   return 1;
 }
 
-int acd66_decompose( word * pTruth, unsigned nVars, unsigned char *decomposition )
+int acdXX_decompose( word * pTruth, unsigned lutSize, unsigned nVars, unsigned char *decomposition )
 {
   using namespace acd;
 
-  acd66_impl acd( nVars, true, false );
-  acd.run( pTruth );
-
-  int val = acd.compute_decomposition();
-  if ( val != 0 )
+  if ( lutSize == 6 )
   {
-    return -1;
+    return acd66_decompose( pTruth, nVars, decomposition );
   }
-
-  acd.get_decomposition( decomposition );
-  return 0;
-}
-
-int acd666_evaluate( word * pTruth, unsigned nVars, int compute_decomposition )
-{
-  using namespace acd;
-
-  acd666_impl acd( nVars, false );
+  
+  acdXX_params ps;
+  ps.lut_size = lutSize;
+  ps.max_shared_vars = lutSize - 2;
+  acdXX_impl acd( nVars, ps );
 
   if ( acd.run( pTruth ) == 0 )
     return 0;
-  
-  if ( !compute_decomposition )
+  if ( decomposition == NULL )
     return 1;
-
   int val = acd.compute_decomposition();
   if ( val != 0 )
   {
     return 0;
   }
+  acd.get_decomposition( decomposition );
 
   return 1;
 }
diff --git a/src/map/if/acd/ac_wrapper.h b/src/map/if/acd/ac_wrapper.h
index 6bde657c0..a4c4bff9b 100644
--- a/src/map/if/acd/ac_wrapper.h
+++ b/src/map/if/acd/ac_wrapper.h
@@ -35,11 +35,9 @@ ABC_NAMESPACE_HEADER_START
 int acd_evaluate( word * pTruth, unsigned nVars, int lutSize, unsigned *pdelay, unsigned *cost, int try_no_late_arrival );
 int acd_decompose( word * pTruth, unsigned nVars, int lutSize, unsigned *pdelay, unsigned char *decomposition );
 
-int acdXX_evaluate( word * pTruth, unsigned lutSize, unsigned nVars, int compute_decomposition );
+int acd66_decompose( word * pTruth, unsigned nVars, unsigned char *decomposition );
 int acdXX_decompose( word * pTruth, unsigned lutSize, unsigned nVars, unsigned char *decomposition );
 
-int acd666_evaluate( word * pTruth, unsigned nVars, int compute_decomposition );
-
 ABC_NAMESPACE_HEADER_END
 
 #endif
\ No newline at end of file
diff --git a/src/map/if/acd/acd66.hpp b/src/map/if/acd/acd66.hpp
index e9dec8a3e..500dab361 100644
--- a/src/map/if/acd/acd66.hpp
+++ b/src/map/if/acd/acd66.hpp
@@ -215,7 +215,7 @@ private:
     local_extend_to( start_tt, num_vars );
   }
 
-  uint32_t column_multiplicity( STT const& tt, uint32_t free_set_size )
+  uint32_t column_multiplicity( STT const& tt, uint32_t const free_set_size )
   {
     assert( free_set_size <= 5 );
 
@@ -250,7 +250,7 @@ private:
     return size;
   }
 
-  uint32_t column_multiplicity2( STT const& tt, uint32_t free_set_size, uint32_t const limit )
+  uint32_t column_multiplicity2( STT const& tt, uint32_t const free_set_size, uint32_t const limit )
   {
     assert( free_set_size <= 5 );
 
@@ -1198,8 +1198,6 @@ private:
 private:
   uint32_t best_multiplicity{ UINT32_MAX };
   uint32_t best_free_set{ UINT32_MAX };
-  uint32_t best_multiplicity0{ UINT32_MAX };
-  uint32_t best_multiplicity1{ UINT32_MAX };
   uint32_t bs_support_size{ UINT32_MAX };
   uint32_t num_shared_vars{ 0 };
   STT best_tt;
diff --git a/src/map/if/acd/acdXX.hpp b/src/map/if/acd/acdXX.hpp
index 5ee6abcd6..74d5df8d9 100644
--- a/src/map/if/acd/acdXX.hpp
+++ b/src/map/if/acd/acdXX.hpp
@@ -46,8 +46,13 @@ namespace acd
 
 struct acdXX_params
 {
+  /* Nymber of inputs of the LUT */
   uint32_t lut_size{ 6 };
+
+  /* Maximum number of variables in the shared set */
   uint32_t max_shared_vars{ 4 };
+
+  /* Run verification */
   bool verify{ false };
 };
 
@@ -228,7 +233,7 @@ private:
     local_extend_to( start_tt, num_vars );
   }
 
-  uint32_t column_multiplicity( STT const& tt, uint32_t free_set_size )
+  uint32_t column_multiplicity( STT const& tt, uint32_t const free_set_size )
   {
     assert( free_set_size <= 5 );
 
@@ -264,7 +269,7 @@ private:
     return size;
   }
 
-  uint32_t column_multiplicity2( STT const& tt, uint32_t free_set_size, uint32_t const limit )
+  uint32_t column_multiplicity2( STT const& tt, uint32_t const free_set_size, uint32_t const limit )
   {
     assert( free_set_size <= 5 );
 
@@ -412,9 +417,6 @@ private:
   bool find_decomposition_bs_offset( uint32_t free_set_size, uint32_t offset )
   {
     STT tt = best_tt;
-
-    /* works up to 11 input truth tables */
-    assert( num_vars <= 11 );
     best_free_set = free_set_size;
 
     /* special case */
@@ -504,9 +506,6 @@ private:
   {
     STT tt = start_tt;
 
-    /* works up to 11 input truth tables */
-    assert( num_vars <= 11 );
-
     /* init combinations */
     uint32_t pComb[11], pInvPerm[11], shared_set[4];
     for ( uint32_t i = 0; i < num_vars; ++i )
@@ -1225,8 +1224,6 @@ private:
 private:
   uint32_t best_multiplicity{ UINT32_MAX };
   uint32_t best_free_set{ UINT32_MAX };
-  uint32_t best_multiplicity0{ UINT32_MAX };
-  uint32_t best_multiplicity1{ UINT32_MAX };
   uint32_t bs_support_size{ UINT32_MAX };
   uint32_t num_shared_vars{ 0 };
   STT best_tt;
diff --git a/src/map/if/if.h b/src/map/if/if.h
index 33621ac92..47fe109ca 100644
--- a/src/map/if/if.h
+++ b/src/map/if/if.h
@@ -552,7 +552,7 @@ extern int             If_CutPerformCheck07( If_Man_t * p, unsigned * pTruth, in
 extern int             If_CutPerformCheck08( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
 extern int             If_CutPerformCheck10( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
 extern int             If_CutPerformCheck16( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
-extern int             If_CutPerformCheck66( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
+extern int             If_CutPerformCheckXX( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
 extern int             If_CutPerformCheck45( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
 extern int             If_CutPerformCheck54( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
 extern int             If_CutPerformCheck75( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
diff --git a/src/map/if/ifDec66.c b/src/map/if/ifDec66.c
index 5c2dce53b..9c486685c 100644
--- a/src/map/if/ifDec66.c
+++ b/src/map/if/ifDec66.c
@@ -24,7 +24,7 @@
 
 ABC_NAMESPACE_IMPL_START
 
-#define CLU_VAR_MAX  16
+#define CLU_VAR_MAX  11
 #define CLU_MEM_MAX  1000  // 1 GB
 #define CLU_UNUSED   0xff
 
@@ -252,7 +252,7 @@ unsigned * If_CluHashLookup2( If_Man_t * p, word * pTruth, int t )
 }
 
 // returns if successful
-int If_CluCheck66( If_Man_t * p, word * pTruth0, int nVars, int fHashing )
+int If_CluCheckXX( If_Man_t * p, word * pTruth0, int lutSize, int nVars, int fHashing )
 {
     If_Grp_t G1 = {0};
     unsigned * pHashed = NULL;
@@ -267,32 +267,7 @@ int If_CluCheck66( If_Man_t * p, word * pTruth0, int nVars, int fHashing )
     /* new entry */
     if ( G1.nVars == 0 )
     {
-        G1.nVars = acd66_evaluate( pTruth0, nVars, 0 );
-    }
-
-    if ( pHashed )
-        *pHashed = If_CluGrp2Uns2( &G1 );
-
-    return G1.nVars;
-}
-
-// returns if successful
-int If_CluCheck666( If_Man_t * p, word * pTruth0, int nVars, int fHashing )
-{
-    If_Grp_t G1 = {0};
-    unsigned * pHashed = NULL;
-
-    if ( p && fHashing )
-    {
-        pHashed = If_CluHashLookup2( p, pTruth0, 0 );
-        if ( pHashed && *pHashed != CLU_UNUSED )
-            If_CluUns2Grp2( *pHashed, &G1 );
-    }
-
-    /* new entry */
-    if ( G1.nVars == 0 )
-    {
-        G1.nVars = acd666_evaluate( pTruth0, nVars, 0 );
+        G1.nVars = acdXX_decompose( pTruth0, lutSize, nVars, NULL );
     }
 
     if ( pHashed )
@@ -312,12 +287,11 @@ int If_CluCheck666( If_Man_t * p, word * pTruth0, int nVars, int fHashing )
   SeeAlso     []
 
 ***********************************************************************/
-int If_CutPerformCheck66( If_Man_t * p, unsigned * pTruth0, int nVars, int nLeaves, char * pStr )
+int If_CutPerformCheckXX( If_Man_t * p, unsigned * pTruth0, int nVars, int nLeaves, char * pStr )
 {
     unsigned pTruth[IF_MAX_FUNC_LUTSIZE > 5 ? 1 << (IF_MAX_FUNC_LUTSIZE - 5) : 1];
-    int i, Length;
+    int Length;
     // stretch the truth table
-    assert( nVars >= 6 );
     memcpy( pTruth, pTruth0, sizeof(word) * Abc_TtWordNum(nVars) );
     Abc_TtStretch6( (word *)pTruth, nLeaves, p->pPars->nLutSize );
 
@@ -327,35 +301,30 @@ int If_CutPerformCheck66( If_Man_t * p, unsigned * pTruth0, int nVars, int nLeav
 
     // quit if parameters are wrong
     Length = strlen(pStr);
-    if ( Length != 2 && Length != 3 )
+    if ( Length != 2 )
     {
         printf( "Wrong LUT struct (%s)\n", pStr );
         return 0;
     }
-    for ( i = 0; i < Length; i++ )
+
+    int lutSize = pStr[0] - '0';
+    if ( lutSize < 3 || lutSize > 6 )
     {
-      if ( pStr[i] != '6' )
-      {
-          printf( "The LUT size (%d) should belong to {6}.\n", pStr[i] - '0' );
-          return 0;
-      }
+        printf( "The LUT size (%d) should belong to {3,4,5,6}.\n", lutSize );
+        return 0;
     }
 
-    if ( ( Length == 2 && nLeaves > 11 ) || ( Length == 3 && nLeaves > 16 ) )
+    if ( nLeaves >= 2 * lutSize  )
     {
         printf( "The cut size (%d) is too large for the LUT structure %s.\n", nLeaves, pStr );
         return 0;
     }
 
-    // consider easy case
-    if ( nLeaves <= 6 )
+    // consider trivial case
+    if ( nLeaves <= lutSize )
         return 1;
 
-    // derive the decomposition
-    if ( Length == 2 )
-        return If_CluCheck66(p, (word*)pTruth, nVars, 1);
-    else
-        return If_CluCheck666(p, (word*)pTruth, nVars, 1);
+    return If_CluCheckXX(p, (word*)pTruth, lutSize, nVars, 1);
 }
 
 ////////////////////////////////////////////////////////////////////////